Definition
A surveillance technique that determines an aircraft's position by measuring the difference in time it takes a signal from the aircraft's transponder to reach several ground receivers in known locations. The system uses these time differences to calculate where the aircraft must be.
Plain English
A way of finding an aircraft's position by listening to its transponder signal from several ground stations at once and comparing how long the signal took to reach each one. From those tiny time differences, a computer works out where the aircraft is.
Context Anchor
Seen in navigation and surveillance discussions, including systems that help determine or verify an aircraft’s position for instrument procedures.
Derivation
From 'multi' (many) and 'lateration', which comes from the Latin 'latus' meaning 'side'. Lateration is the process of finding a point by measuring distances from known sides or reference points. 'Multi' tells you several reference points are involved, which is what makes the position fix accurate.
Why Pilots Care
Supplies accurate position data for air traffic control in remote or mountainous regions where traditional radar cannot reach.
Analogy
It is like locating a person by knowing their distance from several landmarks. One distance gives only a circle of possible places, but several distances together narrow the location down.
Intuition Check
Multilateration is not the same as simply pointing a bearing at the aircraft. It uses distance or timing comparisons from several known points to calculate position.
Example Sentence 1
Air traffic control was able to provide separation services in the mountainous valley because multilateration filled the gap left by limited radar coverage.
Example Sentence 2
Controllers used multilateration data to maintain separation when radar returns were unavailable.